aboutsummaryrefslogtreecommitdiff
path: root/build2/test/script/regex.cxx
blob: c6fba755aa202befeecead30220dacb411246370 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
// file      : build2/test/script/regex.cxx -*- C++ -*-
// copyright : Copyright (c) 2014-2016 Code Synthesis Ltd
// license   : MIT; see accompanying LICENSE file

#include <build2/test/script/regex>

#include <algorithm> // copy(), copy_backward()

using namespace std;

namespace build2
{
  namespace test
  {
    namespace script
    {
      namespace regex
      {
        const line_char line_char::nul (0);
        const line_char line_char::eof (-1);

        // line_char
        //
        line_char::
        line_char (int c)
            : type (line_type::special), special (c)
        {
          // @@ How can we allow anything for basic_regex but only subset
          //    for our own code?
          //
          const char sp[] = "()|.*+?{\\}0123456789,=!";
          const char ex[] = "pn\n\r";

          assert (c == 0  || // Null character.

                  // EOF. Note that is also passed by msvcrt as _Meta_eos
                  // enum value.
                  //
                  c == -1 ||

                  // libstdc++ line/paragraph separators.
                  //
                  c == u'\u2028' || c == u'\u2029' ||

                  (c > 0 && c <= 255 && (
                    // Supported regex special characters.
                    //
                    string::traits_type::find (sp, 23, c) != nullptr ||

                    // libstdc++ look-ahead tokens, newline chars.
                    //
                    string::traits_type::find (ex, 4, c) != nullptr)));
        }

        line_char::
        line_char (const char_string& s, line_pool& p)
            : line_char (&(*p.strings.emplace (s).first))
        {
        }

        line_char::
        line_char (char_string&& s, line_pool& p)
            : line_char (&(*p.strings.emplace (move (s)).first))
        {
        }

        line_char::
        line_char (char_regex r, line_pool& p)
            // Note: in C++17 can write as p.regexes.emplace_front(move (r))
            //
            : line_char (&(*p.regexes.emplace (p.regexes.begin (), move (r))))
        {
        }

        bool
        operator== (const line_char& l, const line_char& r)
        {
          if (l.type == r.type)
          {
            bool res (true);

            switch (l.type)
            {
            case line_type::special: res = l.special == r.special; break;
            case line_type::regex:   assert (false); break;

              // Note that we use pointers (rather than vales) comparison
              // assuming that the strings must belong to the same pool.
              //
            case line_type::literal: res = l.literal == r.literal; break;
            }

            return res;
          }

          // Match literal with regex.
          //
          if (l.type == line_type::literal && r.type == line_type::regex)
            return regex_match (*l.literal, *r.regex);
          else if (r.type == line_type::literal && l.type == line_type::regex)
            return regex_match (*r.literal, *l.regex);

          return false;
        }

        bool
        operator< (const line_char& l, const line_char& r)
        {
          if (l == r)
            return false;

          if (l.type != r.type)
            return l.type < r.type;

          bool res (false);

          switch (l.type)
          {
          case line_type::special: res = l.special < r.special; break;
          case line_type::literal: res = *l.literal < *r.literal; break;
          case line_type::regex:   assert (false); break;
          }

          return res;
        }

        // line_char_locale
        //
        line_char_locale::
        line_char_locale ()
            : locale (locale (),
                      new std::ctype<line_char> ()) // Hidden by ctype bitmask.
        {
        }
      }
    }
  }
}

namespace std
{
  using namespace build2::test::script::regex;

  // char_traits<line_char>
  //
  line_char* char_traits<line_char>::
  assign (char_type* s, size_t n, char_type c)
  {
    for (size_t i (0); i != n; ++i)
      s[i] = c;
    return s;
  }

  line_char* char_traits<line_char>::
  move (char_type* d, const char_type* s, size_t n)
  {
    if (n > 0 && d != s)
    {
      // If d < s then it can't be in [s, s + n) range and so using copy() is
      // safe. Otherwise d + n is out of (first, last] range and so using
      // copy_backward() is safe.
      //
      if (d < s)
        std::copy (s, s + n, d); // Hidden by char_traits<line_char>::copy().
      else
        copy_backward (s, s + n, d + n);
    }

    return d;
  }

  line_char* char_traits<line_char>::
  copy (char_type* d, const char_type* s, size_t n)
  {
    std::copy (s, s + n, d); // Hidden by char_traits<line_char>::copy().
    return d;
  }

  int char_traits<line_char>::
  compare (const char_type* s1, const char_type* s2, size_t n)
  {
    for (size_t i (0); i != n; ++i)
    {
      if (s1[i] < s2[i])
        return -1;
      else if (s2[i] < s1[i])
        return 1;
    }

    return 0;
  }

  size_t char_traits<line_char>::
  length (const char_type* s)
  {
    size_t i (0);
    while (s[i] != char_type::nul)
      ++i;

    return i;
  }

  const line_char* char_traits<line_char>::
  find (const char_type* s, size_t n, const char_type& c)
  {
    for (size_t i (0); i != n; ++i)
    {
      if (s[i] == c)
        return s + i;
    }

    return nullptr;
  }

  // ctype<line_char>
  //
  locale::id ctype<line_char>::id;

  const line_char* ctype<line_char>::
  is (const char_type* b, const char_type* e, mask* m) const
  {
    while (b != e)
    {
      const char_type& c (*b++);

      *m++ = c.type == line_type::special && build2::digit (c.special)
        ? digit
        : 0;
    }

    return e;
  }

  const line_char* ctype<line_char>::
  scan_is (mask m, const char_type* b, const char_type* e) const
  {
    for (; b != e; ++b)
    {
      if (is (m, *b))
        return b;
    }

    return e;
  }

  const line_char* ctype<line_char>::
  scan_not (mask m, const char_type* b, const char_type* e) const
  {
    for (; b != e; ++b)
    {
      if (!is (m, *b))
        return b;
    }

    return e;
  }

  const char* ctype<line_char>::
  widen (const char* b, const char* e, char_type* c) const
  {
    while (b != e)
      *c++ = widen (*b++);

    return e;
  }

  const line_char* ctype<line_char>::
  narrow (const char_type* b, const char_type* e, char def, char* c) const
  {
    while (b != e)
      *c++ = narrow (*b++, def);

    return e;
  }

  // regex_traits<line_char>
  //
  int regex_traits<line_char>::
  value (char_type c, int radix) const
  {
    assert (radix == 8 || radix == 10 || radix == 16);

    if (c.type != line_type::special)
      return -1;

    const char digits[] = "0123456789ABCDEF";
    const char* d (string::traits_type::find (digits, radix, c.special));
    return d != nullptr ? d - digits : -1;
  }
}